Perhaps the best-known attribute of Maeshowe
is its world-famous midwinter alignment.

In the weeks leading up to the winter
solstice, the darkest time of the Orcadian year, the last rays of the setting sun shine through Maeshowe's entrance passage to pierce the darkness of the chambered cairn.

Theories abound as to the significance of this
phenomenon:

Just as the death of the midwinter
sun marked the return of life, did its entry into the tomb symbolise
the continuance of the "life" of those who had died and had been placed
within?

Did the entry of the sun represent rebirth, or a fertility rite of some sort?

Was the shaft of sunlight thought to
carry away the souls of the dead. Or perhaps return them?

Or was it simply a calendar
to remind the ancient Orcadians that the darkest time of the
year had passed and that the light was once again returning?

In truth, we will never fully know the answer,
although we can be fairly certain that it marked the passing
of time - the death of the old year and the birth of the new one - and was an indicator that the days were lengthening again.

To the users of Maeshowe, just as it still does today, the return of the sun heralded a resurgence of light and the return of life to the land.

Although in Orkney the worst of winter often follows the winter solstice, to this day it remains a comforting thought to know the days are lengthening again.

But although we can only speculate as to the
purpose of the alignment, what is clear is the skill of the
Neolithic architects and builders who designed and built Maeshowe.
Not only did they raise the remarkable structure, but it was built
precisely to allow the light at the darkest point of the year to illuminate
their house of the dead.

The Barnhouse Stone and the solstice

Although the common conception is that Maeshowe's alignment is connected specifically to the day of the winter solstice, the
truth is that the cairn is illuminated for a number
of weeks on either side of the shortest day.

Key to this event
is a connection between the howe and the nearby solitary monolith,
known as the Barnhouse Stone.

On the day of the winter solstice, the sun sets
over the top of the Barnhouse Stone, its last rays going on to
illuminate the darkness of Maeshowe's inner chamber.

At first this alignment was thought to be purely
coincidental but later excavations around Maeshowe uncovered a
socket at the tomb's entrance that appears to have at one time
housed a standing stone, similar to the one at Barnhouse.

Local schoolmaster Magnus Spence first recorded
the connection between Maeshowe and the Barnhouse monolith in
1893. While observing the midwinter sunset from Maeshowe, Mr Spence
noticed that:

"The view is very limited,
not extending farther in breadth than a few yards. Strange
to say, in the centre of this contracted view, and at a distance
of forty-two chains stands the monolith at Barnhouse.

"The
alignment formed with this long passage of Maeshowe and the
Standing Stone of Barnhouse indicates directions too remarkable
to be accidental."

(one chain equals 22 yards)

This was also noted in July 1952, when ex-provost P. C. Flett OBE wrote that:

"The alignment formed with this Barnhouse Stone and the long passage of Maeshowe seemed to have peculiar significance, and was too remarkable to be merely accidental."

Mr Spence was correct in his observation, which
has since been expanded by researchers such as Dr Euan Mackie,
a research fellow of the Hunterian Museum, in Glasgow, and Dutch
archeo-astronomer Victor
Reijs.

Six weeks of light

It has now been shown that the centre axis of
the inner entrance passage is directly aligned with the centre
of the Barnhouse Stone. From here, the line travels out to strike
Hoy's Ward Hill, at a place where the sun sets 22 days before, and
after, the midwinter solstice.

This three-week period is referred
to by archeastronomers, such as Alexander
Thom, as a megalithic month (a sixteenth of a year).

The solar flashings

Recent research at Maeshowe revealed another
interesting solar phenomenon - a period when the setting sun briefly
reappears from the side of Hoy's Ward Hill before disappearing
beneath the horizon.

This phenomenon has been christened "flashing",
from the flashes of light apparent seen within the cairn.

An Orcadian symbol

But regardless of the significance of the phenomenon
and the ancient technology behind it, it is not an easy one to
experience given Orkney's notorious winter weather. Very often
low cloud or rain blocks the light of the setting sun leaving
the chamber in darkness.

The phenomenon of the midwinter solstice and
its relevance to Orkney's most famous chambered cairn has captured the imagination
of Orcadians from time immemorial.

The late George Mackay Brown penned what is
perhaps the most poignant account of the event:

"The most exciting thing in Orkney, perhaps in Scotland,
is going to happen this afternoon at sunset, in few other
places even in Orkney can you see the wide hemisphere of
sky in all its plenitude.

The winter sun just hangs over the ridge of the Coolags.
Its setting will seal the shortest day of the year, the
winter solstice. At this season the sun is a pale wick between
two gulfs of darkness. Surely there could be no darker place
in the be-wintered world than the interior of Maeshowe.

One of the light rays is caught in this stone web of death.
Through the long corridor it has found its way; it splashes
the far wall of the chamber. The illumination lasts a few
minutes, then is quenched

Winter after winter I never cease to wonder at the way
primitive man arranged, in hewn stone, such powerful symbolism."

Given the significance of the midwinter solstice to Maeshowe, it seems likely that this was one of the times the cairn was reopened
for whatever ceremonies the Neolithic Orcadians carried out within.
The winter solstice takes place around December
22 and is the time in the year when the sun is farthest south.

This
results in the shortest day and the time when the movement of the
sun across the sky is at its lowest.

The winter solstice can be seen as a turning point and we are fairly
certain that the ancient Orcadians recognised this fact. From the
solstice, the days will gradually get longer and the sun climbs higher
in the sky.

At the winter solstice in Orkney, the sun begins to rise at approximately
9.07am but it is often nearer 10am before it is high enough to be
seen above the surrounding hills.

From there, it makes its way across
the sky, barely above the horizon, before setting again at 3.17pm.
At midwinter we are treated to a total of about six hours of weak sunlight.
A short distance from Maeshowe is the remains
of a Neolithic village known these days as the Barnhouse
Settlement. Within this settlement, by the banks of the Harray
Loch, are two enigmatic structures both of which seem to be aligned
to specific solar events.

The structure known as House Two is aligned so that the light of the rising midwinter sun shined through
its entrance passage to strike the lid of a cist buried into the
floor.
In 1952, an alignment between the Barnhouse Stone, the Watchstone and the Ring of Brodgar was suggested by local man and ex-provost Peter C. Flett OBE. Mr Flett suggested that the to monoliths formed a straight line with the centre of the Brodgar ring, in a north-easterly, south-westerly direction.